Document feeder for moving bed machines such as copiers

ABSTRACT

In a machine having a reciprocating original document handling carriage such as a copier, a roller at the bottom of a sloped ramp rests on the upper surface of the carriage. Documents placed on the ramp slide downward until the leading edge is at the nip between the roller and carriage surface. Movement of the carriage pulls the document from the tray onto the carriage surface for scanning. An additional roller can be included to provide automatic document ejection by pushing the document onto an output tray as the carriage returns.

DESCRIPTION Cross-Reference to Related Application

Application Serial No. 265,517, entitled "Document Ejector Apparatus andMethod Useful for Copiers," by N. K. Arter, M. D. Avritt, W. C. Dodt andM. J. Herman, filed concurrently herewith and assigned to the sameassignee as the present application, claims a separate invention thatwas a direct outgrowth of the basic invention claimed in thisapplication. Although the embodiments originally conceived for utilizingthe document ejector invention claimed in this application differed fromthe embodiments shown herein, the ejector mechanisms shown herein, aswell as shown and claimed in the aforementioned cross-referenceapplication are considered to set forth the best mode presentlycontemplated for implementing the document ejector invention claimedherein. Therefore, the preferred embodiments described hereinbelow aresubstantially the same as set forth in the cross-reference application.

Technical Field

The present invention relates to methods and apparatus for introducingand/or ejecting sheets relative to the carriage or carrier of a movingbed. More particularly, the present invention relates to documenthandling apparatus and methods wherein the document is transported onthe surface of a carriage past a station where an operation is performedrelative to the document. Although not necessarily so limited, thisinvention is especially useful in association with xerographiccopier/duplicators employing carriages which follow a reciprocatingmotion to pass a document to be copied past a scan window. The inventionis particularly well suited for low cost, table-top or compact copiers.

Background Art

Transfer of original document images onto a photosensitive surface incopier devices is obtained by several different techniques. Forinstance, the document is sometimes positioned manually or fed byrollers or belts into a fixed position on a transparent platen so thatmoving optic elements can scan the image. Other copiers use fixed opticsand some form of driven mechanism to move the document past a scanwindow at a controlled rate. Some fixed-optics copiers use drive rollersor belts to propel the original documents across the scan window eitherin single passes or recirculating mode such as is taught by U.S. Pat.No. 2,741,960 by Oldenbloom.

The present invention is primarily concerned with fixed optics copiersthat have a transparent platen containing carriage on which the documentto be copied is placed. The carriage bed is movable in a reciprocatingmotion over an optical scan window as taught by U.S. Pat. Nos. 2,959,095by Magnusson and 3,554,640 by Hoskins. It has also been known to includein a single machine combinations of reciprocating carriages and singlesheet feeders either as separate units with switchable fixed optics oras an integral unit. The sheet feeder is advantageous for its fastoperation but is not compatible with copying books, odd shaped objectsor the like which can be copied on reciprocating carriage devices.

With conventional fixed-optics, reciprocating carriage copiers, thedocument to be copied is manually centered on the platen and a coverclosed on the document to hold it in place during carriage movement.This procedure is awkward for the machine operator and reduces theoverall operating speed of the machine. Addition of a sheet feeder tothe reciprocating carriage machine, either as a separate unit with opticswitching or as an integral element in the structure of the carriage bedwith mechanisms to appropriately position and control the operationbetween stationary sheet feed or moving carriage modes, is unacceptablefor several reasons. For low cost or compact copiers, such alternativesinvolve acceptance of added cost and undesirable complexity as well asextended space requirements in some cases. Further, the machineoperating procedures become more complex which is particularlyundesirable for office copiers.

Unfortunately, the prior art has not suggested any solutions acceptablefor low cost copiers whereby single sheets can be automatically fed toand/or removed from a reciprocating carriage in a fixed-optics system.It is the solution to these problems to which this invention isdirected.

Disclosure of the Invention

The present invention is concerned with methods and apparatus forfeeding and/or removing documents relative to the carriage of acopier/duplicator where the carriage moves in a reciprocal manner sothat a surface thereof passes over a station where an operation isperformed with respect to the documents. Preferably, the operationperformed at the station is optical scanning of the document at a scanwindow as in office copiers, facsimile transmission devices, opticalcharacter readers, and so forth. The document feeder includes means suchas one or more rollers forming a nip with the carriage surface and guidemeans such as a ramp arranged in cooperative relation with the carriage.That is, the nip forming means applies a force at the nip in a normaldirection towards the carriage surface. This nip usually is at anupstream location relative to the station.

The guide means is positioned for directing the leading edge of originaldocuments into the nip between the nip forming means and the carriagesurface so that carriage movement causes a document so positioned to beheld against the carriage surface by the normal (i.e. perpendicular)force and to be carried by the carriage past the station. Preferably,the guide means is on the upstream side of the nip and is directedtowards the carriage surface. Thus, movement of the carriage surfacecauses any document at that nip to be gripped against the carriagesurface with the result that the document is carried by the carriageacross the station.

In the context of the application, upstream is generally intended tomean a location such that a given point on the carriage surface thatencounters both the nip and the station during scanning motions willencounter the nip before encountering the station as the carriage istraveling through the document scanning portion of its motion.Conversely, downstream refers to opposite locations wherein the stationis encountered before the nip as the carriage moves in a nonscanningdirection.

Document feeders in accordance with this invention can include meansdownstream from the station for blocking reverse movement of a documenton the carriage surface when the carriage reverses direction. By sodoing, the document is removed from the carriage surface. The documentremoval means can take the form of one or more rollers and can beselectively operable as by hand or a copier controlled mechanism (e.g.,a solenoid), for example, to perform its document ejection operation.

The document feeder is mountable between its normally operable positionas described above and a non-operating position wherein it is clear ofthe carriage surface thereby permitting book or odd shaped objectcopying. The guide means can include a sensor to provide a signal to thecopier in the presence of a document so that a copy cycle can beinitiated. The guide means can also include gate means for retaining asecond document until copying of the first document is complete.

The present invention is especially advantageous in that the apparatusis manufacturable at a relatively low cost thereby being attractive forlow cost, compact copier applications. Although sometimes characterizedas a "semiautomatic document feeder" or SADF, this invention is wellsuited for adaptation to automatic document feeders. Furthermore, thepresent invention is endowed with the advantage that little or nomodification is required for the copier to which it is attached.

The foregoing and other objects, features, advantages and applicationsof the present invention will be readily apparent to those having normalskill in the art from the following more detailed description of thepreferred embodiments as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a copier including a document feeder inaccordance with this invention.

FIG. 2 is a side view of the FIG. 1 structure in its normal position.

FIG. 3 is a side view of the FIG. 1 structure at the end of the documentscanning movement for the carriage bed.

FIG. 4 is a partially sectioned, side view of an embodiment of adocument ejector mechanism in accordance with this invention.

FIG. 5 is a perspective view of an embodiment of a document feeder andejector in accordance with the present invention.

FIG. 6 is a perspective view of another embodiment of a document ejectormechanism.

FIG. 7 is a partially sectioned view of a portion of the FIG. 6mechanism.

FIGS. 8A-8C illustrate side views showing respectively the start/endposition, the start of scan position and the end of scan position of thecarriage for a copier which uses a three-step reciprocal motion fordocument scanning.

FIG. 9 is a partially schematic arrangement of a document ejectorembodiment useful in the FIG. 8 environment.

FIG. 10 is another document ejector embodiment particularly well-suitedfor a copier in accordance with FIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The exemplary embodiment shown in FIG. 1 includes a copier 10 which hasconventional xerographic components internally for producing copies fromdocuments scanned as a result of the reciprocating motion of carriage12. That is, the image of an original document, or the like, carried bycarriage 12 past a scan window is transferred to a copy sheet from acassette (not shown). These copy sheets are processed internally throughcopier 10 and ultimately deposited in output tray 14. Appropriatecontrol buttons (not shown) are included typically on front panel 15such as on the upper sloped portion thereof. The xerographic processingelements of copier 10 generally form no part of this invention, but byway of example, might be essentially the same as those included in theIBM Executive Copier Model 102.

Housing 20 is pivotally attached by hinge 21 along the rear edge ofcopier 10 so as to overlie the reciprocating carriage 12. Thustransparent platen 24 which is an integral part of reciprocatingcarriage 12 is normally covered by housing 20 when copier 10 is in itsidle state. However, housing 20 can be considerably shorter than asshown since it only needs to be of a size adequate to cover the scanwindow area. In addition, housing 20 is liftable by handle 22 for accessto carriage 12 in general, and transparent platen 24 in particular.Typically, cover housing 20 is made of lightweight plastic and/orcounterweighted for ease in lifting.

Housing 20 has cross members 25 and 26 extending laterally between theside members. An input chute or ramp 28 is attached to bar 25 forreceiving documents to be copied. A freely rotatable roller assembly 30is attached on one side of crossbar 26 whereas a second roller assembly31 is attached to the opposite side of crossbar 26. Assembly 30 includesroller wheels 32 and 33 which are retained so as to rest upon the uppersurface of reciprocating carriage 12. More particularly, and as is bestseen in FIG. 2, the nip formed by rollers 32 and 33 with the uppersurface of reciprocating carriage 12, is such that it is in substantialalignment with the reference line for aligning document leading edges ontransparent platen 24 when carriage 12 is in its rest or idle position.Assembly 31 provides a document ejection function through roller wheels34 and 35 which are arranged to rest upon and rotate with the uppersurface of reciprocating carriage 12.

The operation of the document feed and ejector mechanisms areillustrated in FIGS. 2 and 3. The original document to be copied isintroduced on ramp or guide means 28 so that the leading edge is at thenip between rollers 32-33 and the upper surface of carriage 12 andparticularly at the leading edge reference line for transparent platen24. The copier is then started, and as carriage 12 moves to the right,rollers 32 and 33 apply a force on the document in a normal orperpendicular direction towards the carriage 12 surface. Thus thedocument is gripped between the upper surface of carriage 12 and rollers32 and 33 so that it slides from ramp 28 and is carried by carriage 12across the document scanning window associated with the upper surface ofthe base of copier 10. A fixed optic system internal to copier 10,transfers the image of that document for further processing in aconventional manner internally to copier 10.

Eventually, carriage 12 reaches the end of its scanning motionassociated with its reciprocal movement and assumes a position generallyshown in FIG. 3. Carriage 12 then reverses its direction of movement andreturns to the home position of FIG. 2. It will be recognized that otherreciprocal motion sequences can be involved in the movement of carriage12. For instance, the carriage can follow a three segment scan sequenceas is described later for FIGS. 8-10.

Rollers 34 and 35 are positioned to eject the document thus copied fromthe carriage 12 surface onto exit tray 36 as carriage 12 begins itsreverse direction movement towards its home position. For this purpose,rollers 34 and 35 can include a unidirectional rotational mechanism suchas a pawl and ratchet arrangement that is either continuously operableor selectively operable. Once carriage 12 reaches its position shown inFIG. 3 and begins its reverse direction movement, rollers 34 and 35 stoprotating because they are blocked from turning in the reverse direction.As a result, the document is retained at its extended position so thatit drops towards tray 36. In the event that a long document is copiedsuch that its trailing edge does not pass beyond rollers 34 and 35, itmay be necessary to manually complete removal of the document to theexit tray 36 or to include an additional ejector arrangement as will bedescribed later. Note that the document ejector function associated withassembly 31 can likewise be provided by other means such as an air jet,a movable scraper blade or finger, a vacuum gripper, or any of a widevariety of mechanisms.

In the exemplary embodiment shown in FIGS. 1-3, carriage 12 reciprocatesover the upper surface 23 of copier 10. Surface 23 includes a slot-typescan window to transfer the image of any document contained on platen 24of carriage 12 as carriage 12 reciprocates across that scan window. Whencopying objects that cannot be readily fed through the input ramp andfeed rollers as when copying books, awkward objects, or the like isrequired, the entire housing 20 is pivotable upwardly around hinge 21 toallow placement of the object directly on platen 24 and reciprocation ofcarriage 12 for copying the object.

An assembly 40 for positively ejecting documents from the upper surfaceof reciprocating carriage 12 is shown in FIGS. 4 and 5. Assembly 40 isattached to a housing (not shown) but similar to housing 20 of FIG. 1 asby means of cross members 41, 42 and 43. Mounting frame 44 retains theejector elements in their proper operating position relative to carriage12 via downwardly extending legs. Shaft 45 is journaled between thesedownward extending legs for free rotation and has rollers 46 and 47mounted thereon for engaging the upper surface of carriage 12 with thenip thus formed being generally in alignment with the leading edgereference line for platen 24.

The nip between rollers 46/47 and carriage 12 is also slightly upstreamfrom the scanning window location 49. Pulley 48 is coupled by means ofbelt 50 to a follower pulley 51 mounted on shaft 52 which is alsojournaled for free rotation between the downward extending legs of frame44. Belt 50 causes pulley 51 to rotate which, in turn, drives gear 53and thus gear 54. Frictionally engaging rollers can be used in place ofgears 53 and 54. Gear 54 is connected to shaft 55 so as to drive rollers56 and 57. Accordingly, rollers 56 and 57 receive their rotary drivemotivation from rollers 46 and 47 but rotate in an opposite directionwith respect to rollers 46 and 47.

The engagement and disengagement of rollers 56 and 57 with the uppersurface of reciprocating carriage 12 is controlled by solenoid 58 andyoke 60. Yoke 60 is connected to plunger 64 of solenoid 58 by means oflever arm 65. With solenoid 58 in its unactuated state, spring 66 forcesplunger 64 in a direction so as to rotate yoke 60 around shaft 52, yoke60 being mounted on but freely rotatable around shaft 52. Thus rollers56 and 57 are normally pivoted upwardly so as not to engage the surfaceof carriage 12 thereby allowing documents being scanned to continue tobe retained on carriage 12 as it reciprocates for however many copieshave been selected. Retention of the documents on the surface ofcarriage 12 is augmented by idler rollers 67 and 68 mounted on shaft 69.By mounting shaft 69 in vertically elongated slots 70 and 71, rollers 67and 68 are allowed to continue engaging the upper surface of carriage 12even when rollers 56 and 57 have been pivoted upwardly by the action ofspring 66 as mentioned previously. Rollers 67 and 68 thereby provide adocument retention function for the sheets on the upper surface ofcarriage 12 regardless of the position of yoke 60.

A reflective plate 61 is attached to the lower legs of ejector housing44 in a position to overlie scanning window location 49. This providesreflection of the illumination light to discharge the photo-conductorwhen no document happens to be over window 49 during a scanningoperation. Plate 61 prevents imaging of the underside of ejector housing44 and acts as a guide to restrain documents tending to curl upwardlyunder housing 44.

A document hold-down function is provided by one or more rollers 72attached in freely rotating relation by a reverse-bend spring member 73.Spring 73 is attached to extender 74 from crossbar 76. By thisarrangement, the left edge of a document on platen 24 is held down ascarriage 12 returns towards the left during multiple copy operation. Thereverse bend to spring 73 accommodates the situation wherein the leftedge of carriage 12 passes to the right of roller 72 at the end of ascanning movement.

Input guide assembly 75 is attached to the overall housing by crossbar76 and includes a pair of plates 77 and 78 to form an input chute todirect any documents introduced to the copier into the nip formedbetween rollers 46 and 47 and the upper surface of carriage 12. Plate 80includes a pair of upstanding guide members 81 and 82 which arelaterally movable in slots 84 and 85 so that a document introduced tothe ramp formed by plates 77, 78 and 80 is appropriately centered as itenters the nip between carriage 12 and rollers 46 and 47. Upstandingguide members 81 and 82 can be appropriately interconnected in aconventional manner so that lateral movement of one member 81 or 82automatically adjusts the other member by the same amount.

In operation, the document to be copied is fed face down over plates 80and 77 and under plate 78 until its leading edge is engaged by the nipof rollers 46 and 47 and the upper surface of carriage 12. Carriage 12then commences its reciprocal motion to the right in FIG. 4 either inresponse to manual or automatic machine controls. Movement of carriage12 to the right causes the document to be pinched between surface 27 androllers 46-47 so that the document is carried to the right over the scanwindow (not shown) for imaging, as is well known.

Solenoid 58 is coupled to operating power by appropriate electricalconnections 59 but remains unactuated during most of the copier carriageoperation. Thus spring 66 causes plunger 64 to withdraw and rollers56-57 to disengage from the surface of carriage 12 while idler rollers67 and 68 continue to engage surface 27. If more than one copy is to bemade, solenoid 58 remains unactuated as carriage 12 returns to its homeposition carrying the document with it. Whenever the document has beencopied by a preselected number of times and carriage 12 has moved to itscompleted scanning position, solenoid 58 is enabled so that plunger 64extends to the right in FIGS. 4 and 5 thereby engaging the document byrollers 56 and 57. At that point, the document trailing edge has passedbeyond the nip of rollers 46-47 and surface 27. As carriage 12 returnstowards the left, the action of the belt coupling and gear couplingsfrom rollers 46-47 to rollers 56-57 causes rollers 56 and 57 to drivethe paper positively to the right to completely deposit it in the outputtray (not shown in FIGS. 4 and 5) at least by the time carriage 12reaches its home position.

An additional feature includable with the present invention, if desired,is illustrated in FIG. 5 in the form of a photocell and light sourcecombination 86 which is positioned to detect the presence of the leadingedge of a document at the end of ramp assembly 75. Light from the lightsource contained in assembly 86 is directed at an angle downwardlytoward slot 88 in the bottom plate 77. As long as a document is absent,no light is reflected back to the photocell contained in assembly 86.The presence of the document causes light to be so reflected however,thereby generating a signal over wires 87 to the copier to immediatelystart running copies. A mechanical switch can provide the same functionas photocell assembly 86.

The copier controls are connected by means not shown to terminal block89 to receive the signals on wires 87 as an input and to provideappropriate solenoid 58 operating signals over wires 59. Although notillustrated, another prospective additional feature is to include amechanical gate that is movably positioned in the pathway of input guideassembly 75 preferably at a point above the detector 86. This gate isnormally withdrawn from intercepting relation with respect to documentsfed into assembly 75 but, after complete withdrawal of a document fromguide 75 such a gate can be raised (or lowered) so that it blockspassage of any document introduced to guide 75 while the copier 10 isperforming copying operations on the previously fed document. This gateremains in the document intercepting position and is automaticallywithdrawn upon completion of the copying operation for the previousdocument and the returning of carriage 12 to its home position. Thus anoperator can feed a next document to be copied into the input guide 75during the copying of the preceding document and this second document isimmediately accepted by the document feeder structure upon release ofthe gate and sensing of the document leading edge by the detector 86.

Although not all of the electrical connections for components such asdetector 86, solenoid 58 and the like are specifically shown and thecontrolling electrical equipment associated therewith is likewiseomitted, these devices are well known and are directly usable inconventional copiers with little or no modification. For instance, manycontemporary copiers include microprocessors or controllers forcontrolling the operation of the copier and are easily adapted toperform the appropriately timed input and output signal generatingoperations in association with the detectors, solenoids and the like.However, a self-contained document feeder/ejector is possible byincluding a separate counter mechanism and appropriate feeder and/orejector controls with the SADF thereby avoiding the copier interface.The user sets the SADF counter to the same count as the copier at thestart of the copy run.

FIGS. 6 and 7 illustrate yet another embodiment of a positive documentejecting mechanism in accordance with the present invention. In thisconfiguration, housing 90 retains shaft 91 so that rollers 92 and 93(only roller 92 being visible in the drawings) perform the documentpinching operation relative to the surface of the reciprocating carriagein a manner similar to rollers 46 and 47 in FIGS. 4 and 5. Pulley 94 isattached to shaft 91 so as to turn in conjunction with rollers 92-93 anddrive belt 95 which in turn drives pulley 96 and gear 97. Gear 97 drivesgear 98 thus causing shaft 99 to rotate and, accordingly, rollers 100and 101. This provides the positive document ejection operation similarto the operation of rollers 56 and 57 in FIGS. 4 and 5.

Shaft 102 is arranged to allow idler rollers 103 and 104 to rotatefreely in either direction and also to traverse in a vertical directionthrough slots 105 and 106. The entire assembly including pulley 96,gears 97 and 98 and shafts 99 and 102 are all mounted in yoke 108. Yoke108 is retained in its horizontal position by side frames 111, 112, 113and 114 which are all secured to the upper plate 115 of housing 90 (noteFIG. 7).

Under normal conditions wherein solenoid 116 is not actuated, sidesprings 117 and 118 push upwardly on bar 120 thus raising yoke 108through shafts 121 and 122. A relatively light downward bias betweenyoke 108 and plate 120 is provided to springs 124 and 125 on shafts 121and 122 respectively.

Solenoid 116 has its plunger 126 attached to a pair of cables 127 and128 which are held in position by the yoke assembly 130 and which arefurther attached to plate 120. Actuation of solenoid 116 causes cables127 and 128 to be drawn towards the body of solenoid 116. This imparts adownward force to plate 120 which compresses springs 117 and 118 so asto press yoke 108 and its rollers 100 and 101 downward against thesurface of the reciprocating carriage. Since the rollers 100 and 101 arerotating in a direction opposite to rollers 92 and 93, the documentwhich might happen to be under rollers 100 and 101 is thus driven to theright in FIG. 6 as the carriage moves to the left.

The entire assembly associated with yoke 108 is movable in a verticaldirection depending upon the actuation state of solenoid 116. Further,when solenoid 116 is actuated so as to apply downward pressure throughbar 120 onto yoke 108, this downward pressure is resilient in that it istransferred through compression springs 124 and 125 therebyaccommodating variances in the thickness of the documents being ejectedand the like. Note that the vertical movement of the ejector rollers isaccommodated relative to belt 95 by idler roller 132 as shown in FIG. 6.Idler 132 is held by arm 133 which is spring-biased in an upwarddirection as seen in FIG. 6. Roller 134 is relatively fixed.Accordingly, as the yoke 108 assembly is moved up and down, the changein relative position between shafts 91 and the center of rotation ofpulley 96 is accommodated by the movement of roller 132.

FIG. 8 shows a copier 140 with a carriage 141 that follows a somewhatdifferent reciprocating motion in passing its documents over scan window142. The normal home position is shown in FIG. 8A. Upon initiation of acopy cycle, carriage 141 moves to the right to the position of FIG. 8B.Note that a document introduced to input ramp 144 into the nip betweenroller 145 and the upper surface of carriage 141 is not withdrawn fromramp 144 while carriage 141 moves to the right since the rotary motionof roller 145 during this time is in a direction to keep the document onramp 144 rather than to pinch it against carriage 141.

Carriage 141 at its FIG. 8B position is ready to commence the scanningportion of its reciprocating motion which is done by moving carriage 141to the left until it reaches the FIG. 8C position. Finally, carriage 141returns to its home position (FIG. 8A) with ejector assembly 146 beingoperative during this return motion to move the document off carriage141 towards exit tray 148. If positive document ejection is desired,drive mechanisms similar to those shown in FIGS. 4-7 can be used forejector 146. However, note that the amount of travel in returning fromthe FIG. 8C end-of-scan position to the FIG. 8A home position may beless than half the length of the document on carriage 141. In this case,appropriate gear ratios can be used to ensure that the output rollers146 turn a greater number of times than input roller 145. Among thealternatives to a controlled gear ratio are the FIGS. 9 and 10 ejectorconfiguration.

FIG. 9 shows carriage 141 as it is moving to the right towards its homeposition. Ejector rollers 151 and 152 are attached to motor 154 by shaft150. With switch 155 open, motor 154 is inoperative but rollers 151 and152 are still free to rotate, thereby retaining document 158 in positionon transparent platen 143 for multiple copying operations. When the lastcopy scan is complete and carriage 141 is in the FIG. 8C position,switch 155 is closed by the copier controls to energize motor 154. Motor154 turns rollers 151 and 152 in the direction to drive sheet 158 to theleft with sufficient force and speed to eject sheet 158 into the exittray. Switch 155 is then reopened. Note that a mechanism to raise andlower rollers 151 and 152 can be included in the FIG. 9 configuration.

FIG. 10 illustrates another embodiment for fully ejecting a documentfrom platen 143 during the short return stroke of carriage 141. Roller160 (a feeder roller similar to 145 of FIG. 8 or a separate roller)follows the motion of carriage 141 with pawl 161 on roller 160 engagingratchet 162. Ratchet 162 and shaft 164 attached thereto are free torotate relative to roller 160 absent engagement by pawl 161. Spring 165has one end attached to shaft 164 and the other attached to the machineframe. Spring 165 is wound so as to store energy while carriage 141moves from its FIG. 8A to FIG. 8B positions. A second ratchet 166 isengaged by pawl 168 to prevent spring 165 from unwinding while carriage141 moves in its scanning direction during which time roller 160 freelyrotates around ratchet 162. Therefore spring 165 stores energycorresponding to the motion of carriage 141 from FIG. 8A to FIG. 8B withthis stored energy being available when carriage 141 reaches its FIG. 8Cposition.

At the end of carriage 141 scan motion for the last copy of document170, pawl 168 is released from ratchet 166 by solenoid 172 while pawl161 is released from ratchet 162 by another solenoid, interposer, or thelike (not shown). Spring 165 unwinds driving pulley 174, belt 175 andpulley 176. This drives shaft 178 and therefore wheels 180 and 181 inthe proper direction for ejecting document 170 towards the left.Further, the length of time spring 165 so drivers rollers 180 and 181 isproportional to the time carriage 141 moved from its FIG. 8A to its FIG.8B position. As long as the prescan motion of carriage 141 is equal toor less than the postscan motion, rollers 180 and 181 completely ejectdocument 170 from carriage 141.

The FIG. 10 structure is also adaptable for raising and lowering kickerwheels 180 and 181 for multiple copy operation as discussed previously.In this mode, spring 165 is unwound at the end of every scan motion butonly provides an ejection function when wheels 180 and 181 are lowered.Note that release of solenoid 172 at the end of the first scan stroke iseffective to prevent overwinding of spring 165 during later carriage 141motion for a multiple copy run. In this case, the ejection operationoccurs when pawl 161 is released at the end of the last scan motion.

Although the present invention has been described with particularityrelative to the foregoing detailed description of the exemplarypreferred embodiments, various modifications, changes, additions andapplications of the present invention in addition to those mentionedherein will be readily apparent to those having normal skill in the artwithout departing from the spirit of this invention.

What is claimed is:
 1. In a machine such as a copier having a carriagewhich moves in a reciprocal manner so that a surface thereof passes overa station where an operation is performed relative to a document or thelike, a document feeder comprising:means forming a nip with saidcarriage surface and for applying a force at said nip in a normaldirection towards said carriage surface, and guide means positioned fordirecting the leading edge of a document into said nip between said nipforming means and said carriage surface so that movement of saidcarriage causes a document at said nip to be held against said carriagesurface by said normal force and to be carried by said carriage acrosssaid station.
 2. A document feeder in accordance with claim 1 whichincludes:means operable after the document passes over said station forremoving the document from said carriage surface.
 3. A document feederin accordance with claim 2 which includes:means operable for selectivelyenabling and disabling said removing means from removing the documentfrom said carriage surface.
 4. A document feeder in accordance withclaim 3 which includes:means responsive to said selectively operableenabling means for engaging the document on said carriage surface anddriving said document in a direction away from said carriage surface. 5.A document feeder in accordance with claim 1 which includes:frame meanshaving said nip forming means and said guide means attached thereto asan integral assembly, said frame means including means mounting saidassembly for selective positioning between an operative location whereinsaid nip forming means forms said nip with said carriage surface and aninoperative position wherein said assembly is displaced relative to saidcarriage surface.
 6. A document feeder in accordance with claim 1 whichincludes:means sensing the presence of a document at said guide meansfor producing a signal enabling initiation of movement of said carriage.7. A document feeder in accordance with claim 6 which includes:gatemeans on said guide means movable between a first position forintercepting documents introduced to said guide means and a secondposition for allowing documents to move to said nip, and meanscontrolling said gate means for coordinating said positions thereof inaccordance with operation of said copier.
 8. In a copier having a baseand having a carriage movably mounted relative to said base with saidcarriage containing a transparent platen as part of at least a portionof the surface thereof with said platen having a reference for aiding inalignment of the leading edge of documents to be copied, and includingmeans for reciprocally moving said carriage over a scan window so thatan image is transferred into said copier from said platen as saidcarriage moves through a scan portion of its reciprocating motion, animprovement for said copier of a document feeder comprising:roller meansattached to said copier base and engaging said carriage surface forforming a nip therewith at an upstream location relative to said scanwindow, said nip being located at least in proximity to said platenreference when said copier is ready to initiate a copy scan motion, andramp means attached to said copier base and positioned for directing theleading edge of a document into the upstream side of said nip betweensaid roller means and said carriage surface whereby movement of saidcarriage causes a document on said ramp means with its leading edge atsaid nip to be gripped between said roller means and said platen so thatthe document is carried by said carriage across said scan window.
 9. Adocument feeder in accordance with claim 8 which includes:means attachedto said copier base and engaging said carriage surface downstream ofsaid scan window for removing the document from said platen as saidcarriage moves in a direction opposite from the scanning direction. 10.A document feeder in accordance with claim 9 which includes:frame meansfor attaching said foller means, said ramp means and said documentremoving means to said copier base as an assembly, said frame meansincluding means for selectively positioning said assembly between anoperative location wherein said roller means engage said carriagesurface and an inoperative position wherein said assembly is displacedrelative to said carriage surface.
 11. A document feeder in accordancewith claim 9 which includes:means driving said document removing meansfor propelling the document in a direction opposite said carriage assaid carriage moves in a direction opposite from the scanning direction.12. A document feeder in accordance with claim 11 which includes:meansmounting said document removing means for movement between first andsecond positions wherein said document removing means is respectively inengagement with said carriage surface and displaced from said carriagesurface, said mounting means normally retaining said document removingmeans in said second position, and means responsive to said copier forshifting said mounting means from said second position to said firstposition at the end of the copy run for a given document.
 13. A documentfeeder in accordance with claim 8 which includes:a gate mounted in saidramp means for movement into and out of intercepting relation fordocuments introduced to said ramp means, and means responsive to saidcopier for coordinating operation of said gate means with operation ofsaid copier, whereby a succeeding document is retained by said gatemeans in a ready position and fed to said nip after completion ofcopying of a previously fed document.
 14. A document feeder inaccordance with claim 8 or claim 13 which includes:means producing anoutput indicative of the presence of a document at said nip, and meansconnecting said document indicative output to said copier for initiatingcopy operations.
 15. In a copier having a base with a scan window on theupper surface with a transparent platen incorporated therein and withsaid platen having a reference line for aiding in alignment of theleading edge of documents to be copied, means mounting said carriage tosaid base for reciprocating motion over said base upper surfaceincluding a scanning portion during which said platen passes over saidscan window so that an image of anything on the platen is transferredinto said copier for processing and a reversing portion during whichsaid carriage is returned to its home position, an improvement for saidcopier of a document feeder comprising:an input ramp, roller means, anda frame having said roller means and said ramp means attached thereto asan assembly, said frame being pivotally attached to said copier base formovement between an operative position wherein said roller means andsaid ramp means cooperatively interrelate with said carriage and aninoperative position wherein said platen is accessible withoutinterference from said assembly, said frame being constructed andarranged so that, when in said operative position, (a) said roller meansforms a nip with said carriage upper surface at said platen referenceline, and (b) said input ramp is oriented as a downwardly sloping guidefor directing documents introduced to said input ramp into said nip onthe side thereof opposite said scan window.
 16. The method of feedingdocuments onto a carriage of a copier wherein the carriage moves in areciprocal manner including at least a scan movement wherein documentsare passed over a scan window and a reverse movement in a directionopposite to the scan movement, said method comprising the stepsof:introducing the leading edge of a document to be copied to thesurface of said carriage at a point upstream from said scan window,pressing the leading edge of the document against said carriage surfaceat the point of introduction, and maintaining pressure against thedocument in a direction normal to said carriage surface while allowingthe document to move with said carriage surface during the scan movementof said carriage reciprocal motion.
 17. The method in accordance withclaim 16 which further includes the step of removing the document fromsaid carriage surface upon completion of said scan movement.
 18. Themethod in accordance with claim 17 wherein said removing step includesthe step of applying a force to the document after said scan movementcompletion to propel the document in the same direction as the scanmovement.
 19. In a copier having a base with a scan window and acarriage adapted for receiving documents to be copied on a surfacethereof with the carriage mounted for reciprocal motion over said copierbase, including a scan movement during which the document is passed oversaid scan window, and a reverse movement during which said carriage isreturned to a home position, an improvement comprising:means operable atthe end of said scan movement for engaging the document on said carriagesurface and removing the document from said carriage surface. 20.Apparatus in accordance with claim 19 which includes:means selectivelyoperable between two operating modes for respectively enabling anddisabling the document removing operation of said engaging and removingmeans.
 21. Apparatus in accordance with claim 20 wherein said engagingand removing means includes:means responsive to said enabling modeoperation of said selectively operable means for propelling the documentin a direction away from said carriage surface.
 22. Apparatus inaccordance with claim 19 wherein said engaging and removing meansincludes:means operable after completion of said scan movement forapplying a force to the document in the same direction as the scanmovement.